Fixes for a poor Handbrake

[HarryM1BYT]

Please Note - the compensator exchange service mentioned below, is no longer available from me.

There have been plenty of photographs taken of these fixes, so rather than taking more, I would welcome any photographic contributions for inclusion in this document.

One of the main problems with the handbrake is stretching of the compensator, which is located just below the rear of the console. The two parts of the compensator, its two brackets, are linked by a U shaped 5mm OD and rather soft steel rod fixed only at one end. If the rod were to be straightened out, it would look rather like a 6" nail. In use over the years, the U bend is distorted to roll along the rod, which results in a larger and larger gap between the two parts of the compensator. As the compensator stretches, the only way to take up the extra play in the handbrake is via a nyloc nut adjuster below the handbrake lever. That, combined with poor adjustment at the hub, results in a lot of slack needing to be taken up by the nyloc nut.

The result of the stretching compensator is that you can get the handbrake all set up, adjusted and working well, then as the compensator stretches it will go out of adjustment - eventually you run out of adjustment and the nut jams on its thread.

The more clicks the handbrake makes before it is fully applied, the less leverage you have, so the poorer the handbrake becomes. Your arm muscles become less effective, as the number of clicks increases, as does the mechanical advantage.

I offer a low cost (except for postage costs) exchange service, where I put the U in the rod back to where it belongs and reinforce it by welding, so it can never stretch again. I simply weld the two ends of the U together, equalising the stress, so no further movement of the U along the rod can take place. I also offer a free of cost assistance to swap the compensator over on my drive and if necessary - get the hub adjustment correct.

My modification method can be reproduced at home, if you have access to the basic equipment needed and the final result is quite similar. See my post which includes a stage by stage in photos, of the modification.

You can still buy brand new compensators, but as these are also liable to stretch, fitting a new one without modification does not really resolve the problem.

The compensator connects the single bowden cable from the lever, to the two bowden cables which go one to each rear hub and compensates for any slight difference in adjustment at the hub. It allows for a difference in adjustment of perhaps no more than 5mm, if the difference is more than 5mm you may find the brake only operates on one wheel, so correctly adjusting at the hub is crucial to get an even balance. I have found some returned compensators which have not only suffered stretch, but have also been bent sideways due to the hub adjustments being so unequal.

How to tell if your compensator has an issue

If the hub adjustments are both correct (see below) and your nyloc adjuster nut is showing much more than about 25mm of thread under the handbrake or your handbrake lever needs more than 4 clicks to fully apply it - then the compensator has stretched.

Depending on engine model, you might also be able to inspect the compensator from below. Directly below the compensator / rear edge of the console is an oval shaped rubber bung, which when removed gives sight of the compensator. Under tension, the gap between the two brackets of the compensator should be about 1 to 2mm. Often the gap will have increased to 8 to 12mm. If the issue is not resolved, it is possible for the gap to increase to the point where the compensator could fail completely, though no one has ever reported this as happening.

Compensator Replacement

If the adjuster nut has been tightened to the point where it reaches the end of the thread, it will tear its threads out preventing it coming off. The only way to remove such a nut is to find a way to cut it off. If a 2mm drill bit is fitted in a small drill, then it is just possible with the drill bit mounted in the very end of the chuck, to drill down axially along either side of the nut to make it split into two. A standard long reach 13mm socket is normally long enough to get to the nut, but if over adjusted the nut may require an even longer reach socket. A replacement nyloc nut will then need to be sourced - it has to be a nyloc.

As said, the compensator is located under the rear of the centre console. To get to it, the single philips screw at each side of the front seats needs to be removed (rather awkward, best to move each seat as far forward and as low as is possible). Then the two bolts holding the rear end are removed, which can be found by removing the rear ashtray or coin tray. It should then be possible to lift the entire rear end of the console up and prop it up with a couple of bits of wood.

The carpet in the rear foot well then needs to be lifted out of the way. Lift the seat squab (the bit you sit on) up at its forward edge just enough to ease the carpet from under it. Remove the plastic carpet strips, from where the rear door opens, ease the carpet out from where it goes under the plastic B pillar covers. You should the be able to see a bare steel cover panel, under where the rear end of the console fixed, the same panel into which the two blts fixed. The panel is fixed by three torque bolts and need to be removed. The centre bolt is easy, but to get to the side bolts, the carpet needs to be pushed from underneath to turn it inside out to give you room to work on the torque bolts. Be aware that the edges of the cover panel are usually left very sharp.

Its is not obvious how the compensator is removed, so I'll try to explain a little of that. First you slacken the front nyloc adjuster nut all the way off too maximise the slack in the cables - but do not completely remove the nut. Retaining the cable lug end of the single front cable in the compensator is a small black plastic U shaped retainer clip, squeezing the ends together, the U should come out, thus allowing the front cable's lug to then be extracted from the compensator. Once that is out, the compensator can be turned so it it vertical, then the two ball ends of the two cables to the rear can be disconnected. It reassembles in exactly the same way, with a modified compensator in its place.

Adjusting the Handbrake

Once the compensator has been replaced with a modified one the setting up and adjustment can be tackled. Leave the nyloc nut set at the very tip of its thread.

Jack the rear of the car up and remove (if possible) both wheels at the same time. Looking in through one of the vacated stud holes, rotating it around the 11 to 1 o'clock position you should be able to spot the adjuster using a good light. The adjuster is like a star shape and you are looking at the edge of it, with below it a spring. The fingers of the star can be rotated with a flat bladed screwdriver. Pushing the fingers up, usually takes up the slack, but it is possible that it may work the opposite way depending upon which way the adjuster has been installed. As you turn the wheel, you will usually hear a twang from the spring. The spring serves the dual purpose of acting as a return spring for the shoes and to retain the setting of the star adjustment wheel.

Turn the star wheel just as far as it will go, until the hub is locked solid, then back it off little by little, until the hub just turns freely. A slight rubbing noise from the shoes as the hub turns is acceptable, so long as there is no drag as the hub is turned. Go through the setting two or three times, to get the best possible feel for the ideal setting and the pads being still in place will add their own noise and slight drag. It is important that both hubs are adjusted similarly, because the compensator can only compensate for a misalignment between the two hubs of around 5mm difference between the two cables.

Sometimes it might be worth repeating the above, having pulling the handbrake on a few times, to square up the shoes to the drum. The nyloc nut may need taking up to get the brake to work, then slackened back off to finalize the rear adjustment.

Now the nyloc nut can be adjusted to take up play in the cables. I take up play via the nut, until I feel the brake just starting to byte by rotating the hubs to feel for drag, then back it off a touch until both are again just free.

If you have got it set up right, your handbrake should be having an effect on the first click, working well enough to hold it on many slopes at two clicks and on three hold it on any slope.

Additional handbrake related work

If the above does not resolve all issues, it is worth delving a bit deeper....

Remove the brake calliper and the T30 bolt holding the combined disk / drum on. You may need to slack off the star wheel adjuster, to get the drum over the shoes.

Clean and inspect the inside of the drum, it should be lightly polished where it has been making contact with the shoes during use. The shoes should be barely worn, even on a high miler because they are only used for parking.

The star adjuster is at the top, at the bottom is the bowden cable, which operates an arm to force the two shoes apart when the handbrake is applied. Check the arm is free to move and add a bit of High Melting Point grease to the pivot to prevent seizure. Add a bit of HMP grease to the cable end too. One owner reported that his arm had seized enough to prevent the shoes fully returning.

Some owners report a creak from the drums as they get in and out of the car - this is due to a slight amount of movement of the shoes against the back plate. If the noise bothers you, smear a trace of HMP grease where the shoe edges contact the back plate.

Grease absolutely must not be allowed to get onto the friction material of the shoes!

Aftercare

The only use the handbrake normally gets is once at a stop, for parking, many owners fail to use the handbrake even when stopped in traffic and this is especially true of an auto. Restricted to just such use, the inside of the drum can become rusty. Rust acts like a lubricant when it is between the drum braking surface and the shoe, which results in a poor handbrake come MOT time. The Rover workshop advised method of sorting this issue out, is to drive the car around a car park, with the handbrake lightly applied to clear the rust out.

I prefer an alternative method which keeps the handbrake working throughout the year. Rather than using the clutch or footbrake to hold the car, I long ago developed the good habit of always using the handbrake to the full, even during a brief stop in traffic. Which is basically why the handbrake issue was one of the first things I tackled when I first got the car - I like handbrakes to work!

For the Rover 75 I slightly modified my habit - As the car comes gently to a stop over the final yard or two, I apply the handbrake one click, which is enough to slow the car and keeps the drum completely free of rust all of the time.

If you sort out the issues above, you are almost guaranteed an handbrake which - instead of the MOT testers making allowances for the fact that it is a 75, may well have the testers complaining it is just too good. On the left a modified and welded up compensator, ready to be installed. Original stretched item on right, awaiting repair.

How to modify a stretched or a new compensator

You will need a good vice, hammer, angle grinder (or drill) and a welder.

Note - I have fully documented this with a description and step by step photos in this thread - https://www.the75andztclub.co.uk/for....php?t=151848&

If you refer to the photo below, the right hand compensator is the original stretched compensator and just on the right, you can see a head of the pivot pin, with its smaller head facing you. The small end needs to be ground away completely, to enable the pivot pin to be punched out, which enables the single cable bracket to be removed to reveal the U in the rod. The stretched link rod, then needs to be tightly gripped in the corner of the vice very tightly and close to the twin cable bracket.

The U needs to then be repeatedly hammered so it gradually moves back along the rod, nearer to the 'nail head' making the free end of the 'nail' longer. As you progress you may need to reassemble a few times to test your progress, but the end result should be a gap of around 1mm between the two brackets, with the assembly and brackets on a flat surface. When complete, the free end of the 'nail' should extend around 5mm beyond the head end, at which point the compensator is ready for reassembly.

Reassemble, crimping the small end of the pin, where you ground its head off, back into its hole using the vice. That needs to be then welded over, to prevent the pin coming back out.

Grip the free end of the rod, free end upper most in the vice, so that enough of the rod protrudes to enable it to be hammered over to meet the 'nail head'. Once tight up with no gap, the two can be welded together, joining the upper surface of the head, to the bent over end. A new compensator will simply need the above final part to be done, to make it ready for use.

Job done and if your welding is halfway reasonable, it should never stretch again. The only weakness in the design was the fact that there was no support for the free end of the rod and having welded the two ends together, it becomes many times stronger than before. Your adjusted handbrake should then never need adjustment again.

Notice the difference in the gap between the two metal brackets in the photo below. On the left a modified item with the correct gap which is about 1mm, on the right a slightly stretched item with a gap of around 7mm.

If you don't feel up to the task of modifying a compensator, I offer a ready to fit version, compensator exchange service.

[carguy143]

What a nice little write up, a good read too.

Rik.

[Arctic]

Excellent write up and if followed will result in an handbrake you can have faith in for (Harry)

these are recent updated photo's of the compensators
First left a new one as would have been fitted to the car from production.

Rear middle original compensator stretched to 15mm from 3mm new

Far right the first ever welded one which i fixed to my Tourer and removed last week in favour of the Stainless Steel Shackle compensator as i was not 100% behind the welded one and as such never sent none out even though it seemed to work fine, it was always in my mind about that mild steel chocolate bar thinking is it going to last my hand brake did move from 3 to 5 clicks over a period of 6 months but that could well have been the shoes.

Front and foremost the Stainless Steel Compensator which can not stretch and i am 100% behind.

I am at the moment looking at another idea which i hope is less work and easier to produce even though the fitting will remain the same.

[HarryM1BYT]

Originally Posted by Arctic

Far right the first ever welded one which i fixed to my Tourer and removed last week in favour of the Stainless Steel Shackle compensator as i was not 100% behind the welded one and as such never sent none out even though it seemed to work fine, it was always in my mind about that mild steel chocolate bar thinking is it going to last my hand brake did move from 3 to 5 clicks over a period of 6 months but that could well have been the shoes.

Absolutely nothing wrong with welding them up. The 5mm rod is just mild steel, but I have never seen one where the steel has actually stretched, nor would I expect to see one. The only issue is the unsupported U is moved by tension along the rod. There was never any issue with the materials used, only the design where it relied upon the U in the soft rod to not move in use.

5mm mild steel rod has a breaking strain rated in tons. Doubling that up, as I do by welding, makes it several times stronger than is needed for this application.

Try forming a U in a bit of soft copper and hooking it over something and pulling. Then trying the same with the end of the U wrapped around itself and pulling. You will find a vaste difference in strength between the two.

I have absolute confidence in either the welded or shackle method of modification. Both completely resolve the issue.

[Girlie Swot]

I've been having problems with my handbrake and this is very, very useful

[HarryM1BYT]

Originally Posted by streatfk

I've been having problems with my handbrake and this is very, very useful

I will add some photos if anyone offers to donate some or as soon as I get some taken myself. I have a rear disk/ drum swap due once the weather permits it.

[COLVERT]

Why not just weld the top of the U shaped rod to the housing above it. Would only take 5 seconds and the rod would not be able to slip around the pin.





Colvert.


( The obvious is usually the hardest thing to see. ) Lol.

[HarryM1BYT]

Originally Posted by COLVERT

Why not just weld the top of the U shaped rod to the housing above it. Would only take 5 seconds and the rod would not be able to slip around the pin.

Colvert.

( The obvious is usually the hardest thing to see. ) Lol.

Two reasons - The rod needs to be free to allow the other two parts some rotational movement and the two housing are compared to the rod quite thin steel, making it less easy to weld the two.

Moving the U back to where it belongs and welding the ends of the U rod together, more than doubles the strength of the compensator, but still allows it to do its job exactly as before.

[FROGGY]

I'm with Colvert on this one.
I know lots of folks have spent hours on this problem, with some well thought-out solutions, but studying the pics of the compensator, surely any horizontal or vertical movement of the twin cable section takes place on the "nailhead" (bottom) part of the rod, where it can pivot.
I would like a compensator in my hand to check this out, but feel fairly certain that this may be all that is needed.

[HarryM1BYT]

Originally Posted by FROGGY

I'm with Colvert on this one.
I know lots of folks have spent hours on this problem, with some well thought-out solutions, but studying the pics of the compensator, surely any horizontal or vertical movement of the twin cable section takes place on the "nailhead" (bottom) part of the rod, where it can pivot.
I would like a compensator in my hand to check this out, but feel fairly certain that this may be all that is needed.

You do really need a compensator in your hand, to actually see how it works. On the unmodified unit - The twin cable bracket is not only able to rock horizontally from side, but the two brackets can rotate a little way in relation to each other. That ability to rotate adds a little extra abilty to compensate for differences in the two rear cable lengths. The twin cable bracket alone cannot swivel very far, due to it having such a short distance between the two cables. The abilitity to also rotate adds a little extra movement.

The rod diameter is quite a bit less than the internal width within the brackets it passes through, so there is room for quite a bit of rotation. Weld either of the parts one to another and you loose some of that freedom to rotate.

I was keen to make sure that my modification allowed the compensator to work as it was designed to, but to fix the design fault which allows it to stretch - I think I have achieved that. I have turned out in excess of 50 of this modified design so far and they most certainly work.